Thursday, 31 January 2008

I like this:If anyone's wondering, the equation ER/EI is "energy return" divided by "energy invested" (more info here), the point being that the oil (and coal and gas) we extracted in the past was easy to get at, so the energy return was large compared to the energy invested.

Today, the EROEI (as it's more commonly known) ratio is a lot lower, as we go for difficult-to-get fossil fuels, such as polar oil and tar sands, and is falling as each year goes by. That means that there's less energy for the human race to live on, just as demand is rising. I expect you don't need me to tell you that means trouble...

So now you know one of the incentives for us buying a wood - it grows renewable fuel for us!

So what's the EROEI for a chainsaw? Well, we've only burned about 12 litres of petrol so far, which might move a small car 120 miles or so, and contains in the region of 500MJ of energy. That fuel has enabled us to cut 10 tonnes of wood (at a conservative guess, it could be a lot more), which once seasoned could yield about 150,000MJ of energy. I think that's a better return than burning it in a car! I think I'll go and burn some more tomorrow...

Today is extremely windy and wet. Nonetheless, we may pop up to the wood for a short time to meet the guy who will be thinning our oaks for us in a few weeks, to discuss the operation. This will depend on whether he has time today though.

Thankfully Friday and Saturday look like being at least partially sunny, so we hope to do a little tomorrow and then a full day Saturday.

Saturday, 26 January 2008

We saw all kinds of life in the wood yesterday. As soon as we'd parked inside the gate, and got out the car, we heard a rather strange noise coming from the among the grass and brambles. As we peered into them we got a glimpse:As we edged closer we got a better view:And realised it was two male pheasants fighting:Then they decided that humans were a greater risk than stopping the fight, and did a runner:Just a short distance up the wayleave, we found a huge number of prints, which we think were from deer, but feel free to correct us if we're wrong!There'd been similar activity at our pond, which was trampled:The prints looked like deer again:although there was also evidence of boar activity in the last few days just a few metres away, in the wood the side of the footpath:There's also a lot of plant life springing up, including new growth on patches of moss, especially in the area we've coppiced so far:There's also what we think are bluebells sprouting all over the place, including in the middle of the rides:And of course, the honeysuckle is getting an early start in, before the leaves are on the trees:We're pulling bits of honeysuckle whenever we can be bothered though - a certain amount of it in the wood is OK, and even good for wildlife, but it can also smother young trees, so you need to keep an eye on where it's growing. For example, check out this picture from an earlier post where it was smothering a young oak, right at the start of our coppicing:OK, time for some update pictures on our progress. Just for a remainder, here's howit looked at the start:And here's how it looks now:The last one of those three is looking back towards the entrance from the edge of where we've coppiced to so far. Before we started you could see through this bit, it was so dense!

Oh, and here's what happens if you misjudge how a twisted log will roll and flex while you're cutting it:It's something you try and avoid, but it inevitably happens occasionally. The solution is to lift the log in such a way that the cut opens up and frees the saw. A lot easier with two people than on your own!

I though it would be interesting to make a few videos of different tree felling techniques. So, for starters, here's me making a standard felling cut, then using a felling lever to give the tree a push at the end. It takes about 45 seconds from starting the saw to the tree falling:

As well as managing our wood, Chestnut Coppice, we are also managing Sweep Wood, which my parents have just bought, and is adjacent to ours. At the moment we're just keeping an eye on it, while a management plan is put together for it. Although it is predominantly chestnut coppice, with oak standards and some birch, it also has a variety of other trees that aren't present in our own wood. For example...

Pollarded Hornbeam, along the boundary with a field:(see an earlier post on pollarding here)

Ash - here's one that fell over recently, and clearing it up will be one of the first jobs (no rush though, as it's pretty much on the ground and not causing any danger):Yew, which can live for at least 2,000 years!Freaky chestnut roots:There's also Hazel and Poplar, and quite a bit of Holly, and a good range of other plants, such as these, which I think are Bluebells, and Lords & Ladies:Domestic garden invaders (I think...) at one end:Here you can see the new growth of bluebells just coming up amongst the Hazel and Poplar coppice:All in all, an interesting and varied wood, which we're looking forward to being involved with.

Mike

p.s. we also spent most of today coppicing in our own wood, but that'll have to be posted tomorrow, as it's getting late...

OK, so everyone knows we are coppicing our wood, which basically means felling the trees and cutting the stump off close to ground level, so that new growth comes up from the base in the spring, and gives several stems per plant. However, another alternative approach is pollarding, which is basically the same as coppicing, except you leave a length of trunk. Here's one we left like that today:So why would you do that? Well, instead of the new growth coming out at ground level, it comes out at the top of the stem, and after its grown looks like this hornbeam (which is in Sweep Wood, next door to ours:Here's a close-up:And if you keep doing it every time you cut it, you end up with something like this very old hornbeam pollard (again in Sweep Wood):So what are the advantages of pollarding?

It makes the trees look cool! :-)

A pollarded tree can live to a great age, much longer than the same tree left to itself would.

Because the new growth starts at some distance off the ground, it is harder for browsing animals (deer and rabbits) to damage the new shoots.

When the older pollard stumps eventually die (while the newer ones are still alive), they can form an excellent wildlife habitat.

We're only making our pollards one or two feet high, as our main aim is for the future wildlife habitat, and also variety in the appearance of the wood. We're also just doing the odd one or two like this, to see how it works out.

Traditionally, chestnut is pollarded at a low height to mark the edge of each "cant" or "coupe" that has been cut. There's several old pollards in our wood like this, but the boundaries they once marked no longer seem to be in use.

Friday, 25 January 2008

Well, the event yesterday was a great success, with about 75 people there!

The presentations were geared towards woodland owners, and started with Tom Vosper (CEN) explaining how a wood-fuel boiler works, and what goes wrong if there are leaves, bark, moisture, sticks, etc. in the fuel. Julian Morgan-Jones of SEWF then talked about the wood-fuel market in the SE, which he sees growing at several hundred percent a year for at least 5 years. There were then three case studies from woodchip producers, sharing valuable practical experience and taking questions. Finally, LC Energy spoke about their wood-fuel supply model, and a representative from Forestry Commission and SEEDA talked about capital grants that will be available for woodchip producers this year.

I think the most interesting little snippets of information I picked up were:

"Moving grate" style wood-fuel boilers can tolerate a higher moisture content in the fuel, as the wood chips are in the combustion zone for longer, so have time to dry out. (more info on moving grate systems).

Too much bark in wood-fuel leads to high ash production.

Too many leaves in wood-fuel leads to corrosion of the boiler, as leaves contain chlorine.

It's easier to stack the wood and let it dry naturally, then chip it, than to chip it green and try to dry the chips. Green chips are much more likely to compost, so need turning regularly.

It's easier to take the chipper to the wood, and then transport the chips, then to bring the wood to the chipper.

If you're a wood chip supplier, you must have spare parts in for your machinery, or a big stock of chips, as supplying parts can sometimes take a while, and people are depending on you for fuel.

There was of course much more, but the above was stuff that was new to me. We're not planning to do any woodchip ourselves, though if everyone in the woods got together, there might be scope for doing it once a year. It was an interesting day to make contacts anyway, both for work, and for our wood - Tracy spent a lot of time talking to people about SWOG (Small Woodland Owners Group).

Wednesday, 23 January 2008

Tomorrow we're both off to a training event for wood-fuel producers, run by WoodNet. The course details are here. We've been to quite a few WoodNet courses before, but our reasons this time are different. I'm going on behalf of work (Ashden Awards), while Tracy's going because there's a chance (nothing definite yet) that she might do some work for WoodNet in future, so it's a chance for her to meet with some of the people again and see how things run.

Sunday, 20 January 2008

I realised that there's several old, and amusing, videos of Pete that weren't on here, so here they are. None is longer than a few minutes. If you're not interested in cockatiels, there's a post about the wood below this one...

Yesterday was dry, though cloudy and pretty windy, so we were fortunately able to go to the wood. When we got there we found that the upstream side of the culvert was full to the brim (sorry I didn't take a photo). The culvert pipe had become blocked because of the amount of leaves and twigs that had been washed down in the heavy rain of the past few days.

Fortunately there was a simple solution - I stood in the downstream end and shoved a long chestnut stem up the pipe. After a bit of jiggling around, there was a glugging noise and the water came rushing through.

While we were down there, I took the opportunity to dig a small ditch to divert water away from the ride and through the culvert. I'll probably enlarge it later in the year, but it's doing the job for now:

Lighting the fire was more tricky with the wind, but Tracy managed it, and then we got on with coppicing as normal. With it being windy I had to be a bit more careful felling - sending trees in the direction the wind was blowing, and using split-level felling cuts for more control.

We also met our neighbours Colin and Sue, who were up there with their son, digging a pond and dealing with the rhododendron they'd uprooted a couple of weeks ago. We also had a local friend, Richard, drop in - he's hoping to come and help out a bit in February.

There was one interesting find for the day:It had a been chewed a bit, probably by a dog, but it was interesting to see that there must be some reasonably sized deer around.

And finally, before we left for the wood, I got a good sunrise photo out of our back window:Mike

Friday, 18 January 2008

Well, I much prefer Blogger to our old blog host. I've found I can even add a slideshow of our recent pictures from Flickr. You see it to the right of this page, near the top. Below it are our recent videos, followed by a news feed from EnergyBulletin, links to several websites (includes blogs by our woodland neighbours and the overall website for the large wood of which ours is a part) and finally the archive of old posts.

We've moved our blog here due to the inappropriate adverts being placed on the old one without our knowledge.

I've imported all the old posts (but not the comments), so you won't miss anything. There's also some new features on this one which I'll be playing with. For example, on the right hand side of the page you'll see a "video bar" which shows some of our most recent videos we've put on youtube.

Well, we didn't have to wait till Saturday to go to the wood! Yesterday I had to run an errand in the afternoon, and as the rain had stopped and made way for the sun, I thought it would be a good opportunity to get a couple of hours in at the wood, and catch up on my work in the evening...

When we got there Tracy noticed these interesting mushrooms growing inside a tree:

Sadly it is one of the trees that needs to come down - it's grown all twisty and is in the shadow of another oak, and we want to make room for some younger oaks to grow up. Also it will hopefully make some good bowls, as it's covered in burrs.

We got quite a lot done in the 2 hours we were there, as we didn't bother with a fire, didn't need to take spare fuel for the saw and took a flask of coffee rather than making one there.

With the fire not lit, we took the opportunity to fell all the trees that would have landed in it otherwise:

We really feel like we're making some progress now, we think we're over half way done:

The track has mostly dried out after I dug the little channel on Saturday:

Though it's throwing it down again now, so it might be underwater again - it won't stop happening until we dig another ditch to divert water through the culvert.

After the week's rain, we were expecting to find quite a bit of water in the wood. But we didn't expect to have a little waterfall!

Or if you'd like to see it moving, and with sound:

The other end of the culvert was working nicely too:

However, what we'd forgotten to allow for was the fact that with all the leaves and twigs, the stream was liable to spread out upstream:

and make its way onto the track by a different route, with this result:

It wasn't too difficult to remedy though - I just cut a notch in the bank at the edge of the track on the downstream side to let the water drain off and back into the stream. I think one of this summer's jobs will be to dig a ditch on the upstream side to guide the water into the culvert.

Our pond wasn't affected much by the rain, as it is fed from a spring, but Tracy took the opportunity to rake some of the leaves out of it:

The rest of the day was coppicing as normal, and we also met up with our neighbour Colin, and had a look at the source of our stream, which is in his wood.

There was one awkward tree which seemed to have forked not far off the ground, and so each stem had to be felled separately:

After felling it, it turned out that it was actually two independent stems, which had merged for a short part of their length, as can be seen from the sections below:

It looks like it's going to rain most days this week, and I've got to work 5 days as well, so it'll probably be next Saturday before we're up at the wood again.

One of the three rivers in Rye is the Brede, which flows through a lock and sluice, used to keep the high tide out and control the river level. We live near it, so after all the rain this week, I thought it would be interesting to go down at high tide, when the lock is shut. This keeps the tide out, but also means the flow coming down the river simply piles up until the tide drops. Here's the the lock:

As you can see, the tide (on the right) is higher than the river. The boat had drifted in there - I mentioned it to an environment agency guy I happened to see, but it wasn't theirs, and apparently this wasn't the first time it had been seen drifting down the river...

Once the tide started to fall, the gates opened, giving a strong flow through them:

Here's a few pictures of the river as normal, and in flood:

We've heard it can actually get a lot higher than this...

These guys didn't seem to mind though. Look out for one Mallard chasing another!